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N Arai

Publications and source records attributed to N Arai.

At least 163 records · Page 9Linked to original sources
PubMed1994

Effects of KCA-098 on bone metabolism: comparison with those of ipriflavone.

We previously found that 3,9-bis(N,N-dimethylcarbamoyloxy)-5H- benzofuro[3,2-c]quinoline-6-one (KCA-098) inhibited bone resorption in organ culture. In this study, to determine if KCA-098 is therapeutically applicable for the treatment of osteoporosis, we compared the effect of KCA-098 on bone tissues with that of ipriflavone, a drug that is clinically used for the treatment of osteoporosis. Both KCA-098 and ipriflavone inhibited parathyroid hormone-, prostaglandin E2-, 1 alpha,25-dihydroxyvitamin D3- and interleukin 1 beta-induced bone resorption of fetal rat bones, but the inhibitory activity of KCA-098 was more potent than that of ipriflavone. In fact, the effective concentrations of KCA-098 were 10 to 100 times lower than those of ipriflavone. Oral administration of KCA-098 (1 and 3 mg/kg) or ipriflavone (100 mg/kg) to ovariectomized rats on a low-calcium diet increased the breaking force and bone density of the femora, indicating that KCA-098 is an effective on the whole animal as ipriflavone. Furthermore, KCA-098 increased the length and calcium content of 9-day chick embryonic femora cultured in vitro, whereas ipriflavone did not, suggesting that KCA-098 had a direct stimulatory effect on bone mineralization. Therefore, KCA-098 seems to be more potent than ipriflavone in stimulating bone tissue formation and may thus be expected to become a useful agent for the treatment of osteoporosis.

24,25-Dihydroxyvitamin D 3↗
PubMed1993

cAMP activates the IL-5 promoter synergistically with phorbol ester through the signaling pathway involving protein kinase A in mouse thymoma line EL-4.

Expression of the IL-5 gene in T cells is induced in response to Ag stimulation; however, functional analysis of the IL-5 gene has been limited by lack of an appropriate transfection assay to facilitate measurement of the IL-5 promoter activity in response to T cell activation signals. Here, we describe a transient transfection system with which the IL-5 promoter activity can be assayed quantitatively. Using mouse thymoma line EL-4 cells, which produce several lymphokines including IL-2, IL-3, IL-4, IL-10, and GM-CSF in response to PMA, the effect of cAMP on IL-5 production was examined. These cells produce a low level of IL-5 when stimulated with PMA alone; however, N6, O2-dibutyryl cAMP (Bt2cAMP), in combination with PMA, augmented by more than tenfold the IL-5 production at the mRNA and the protein levels. Likewise, a transient transfection assay revealed that Bt2cAMP activated the IL-5 promoter more than tenfold, in a PMA-dependent manner, thereby indicating that two signals, PMA and cAMP, are required for optimal activation of the IL-5 promoter. Activation of the IL-5 promoter in response to Bt2cAMP and PMA depends on the region spanning from nucleotide position -1,200 to +33 relative to the transcription initiation site. Action of cAMP on the IL-5 promoter is mimicked by cotransfection of the expression plasmid containing cDNA encoding the catalytic subunit of protein kinase A, hence, cAMP probably exerts its action through the signaling pathway that involves protein kinase A. In contrast, Bt2cAMP almost completely inhibited the PMA-dependent activation of the endogenous IL-2 gene as well as the transfected IL-2 promoter. These results indicate that the IL-5 gene in EL-4 cells is positively regulated by cAMP in a manner opposite that for the IL-2 gene.

Animals↗
PubMed1993

Purification of the 120 kDa component of the human nuclear factor of activated T cells (NF-AT): reconstitution of binding activity to the cis-acting element of the GM-CSF and IL-2 promoter with AP-1.

The cis-acting element of the granulocyte-macrophage colony-stimulating factor (GM-CSF) promoter, CLE0, is required for stimulation dependent expression of the GM-CSF gene by phorbol ester (PMA) and calcium ionophore (A23187) in T cells. We recently obtained evidence that NF-CLE0 gamma, one of the CLE0-binding factors, is similar to the nuclear factor of activated T cells, NF-AT. In the present study, we show that the affinity-purified NF-AT from nuclear extracts of human Jurkat T cells stimulated with both PMA and A23187 bound strongly to the CLE0 element and formed a NF-CLE0 gamma complex. This DNA-protein complex was competitively inhibited by oligonucleotides containing NF-AT and AP-1 binding sites, suggesting that the CLE0 gamma complex is identical to NF-AT and contains AP-1 proteins. Here, one component of NF-AT with an apparent molecular mass of 120 kDa on SDS-polyacrylamide gel electrophoresis was purified to near homogeneity by Mono Q chromatography. The purified 120 kDa protein reconstitutes NF-AT binding in combination with recombinant cJun/cFos heterodimer. Furthermore, we demonstrate that binding of this 120 kDa protein to both the NF-AT and the CLE0 sequences can be reconstituted with the addition of affinity-purified Jurkat AP-1 proteins. These results indicate that NF-AT (NF-CLE0 gamma), which is composed of the 120 kDa nuclear protein and AP-1 proteins, regulates the stimulation-dependent expression of the GM-CSF gene as it does the IL-2 gene.

Base Sequence↗
PubMed1993

Foamy spheroid bodies in the globus pallidus and the substantia nigra pars reticulata: an investigation on regional distribution in 56 cases without neurodegenerative diseases.

In order to clarify the sites of predilection for foamy spheroid bodies (FSBs) their regional distribution was studied in 56 persons (30-98 years) without neurodegenerative diseases. Variable amounts of FSBs were observed in approximately 30% of cases and favoured the rostro-ventral parts of the globus pallidus (GP), including the ventral pallidum, and/or the substantia nigra pars reticulata (SNr). The results strongly suggest that FSBs develop during aging and are a hitherto undescribed pathological hallmark for degeneration of the GP and the SNr.

Adult↗
PubMed1993

Osteopontin mRNA expression during bone resorption: an in situ hybridization study of induced ectopic bone in the rat.

To study the relationship between the expression of osteopontin mRNA and ectopic bone formation and resorption, in situ hybridization using 35S-labeled RNA probes was performed on ectopic bone that was induced in an experimental rat model. The expression of type I collagen and osteocalcin in this ectopic bone was also examined. After 6-week-old male Wistar rats were injected intravenously with colchicine at a dose of 1 mg/kg, trabecular bone-like ectopic calcified tissue had formed in the medial bone marrow cavity of the tibia on day 4, and then continued to increase progressing forward to the distal cavity. On day 8 peak growth was attained, after which it was resorbed within 4 days as a result of osteoclast recruitment. Subsequent in situ hybridization of sections of the ectopic bone at 4, 6, 8, and 10 days after this colchicine treatment revealed that high levels of the type I collagen mRNA were expressed in the osteoblasts of the mineralized ectopic bone surface, not only during the formation period but also during bone resorption. Although osteocalcin showed no specific signals throughout the experiments, osteopontin mRNA was expressed temporarily at day 10 during the initial phases of ectopic bone resorption, primarily in both osteoblasts and osteocytes and further in some osteoclasts. These results suggest that de novo synthesis of osteopontin is closely associated with bone resorption and could possibly be required to initiate and mediate this biological process.

Animals↗
PubMed1993

Reconstitution of the functional granulocyte macrophage colony stimulating factor promoter: evidence for distinct activation mechanisms that mediate the response to phorbol ester/calcium and human T cell leukemia virus type I Tax signals.

Functional elements in the promoter region of the mouse granulocyte-macrophage colony stimulating factor (GM-CSF) gene were assessed by constructing chimeric promoters linked to the bacterial chloramphenicol acetyltransferase (CAT) gene and by employing a transient transfection assay of human T cell leukemia Jurkat cells. We previously reported that CLE2/GC-box (at positions -95 to -73, which is homologous to the NF-kappa B binding site) and CLE0 (at positions to -40) of the mouse GM-CSF promoter are essential for transcriptional activation in response to phorbol-12-myristate-13-acetate (PMA)/calcium ionophore (A23187). Here we show that CLE2/GC-box and the NF-kappa B binding motif are functionally interchangeable and that CLE2/GC-box and CLE0 as a unit activate the basic GM-CSF promoter in response to PMA/calcium signals. This unit is also capable of activating heterologous promoters in response to PMA/calcium signals. In addition, we show that Tax, the trans-activator encoded by human T cell leukemia virus type I (HTLV-I), activates the GM-CSF promoter via CLE2/GC-box without the involvement of CLE0. These results indicate that PMA/A23187-dependent and Tax-dependent activation of the GM-CSF gene proceeds through distinct mechanisms.

Base Sequence↗
PubMed1993

The granulocyte-macrophage colony-stimulating factor promoter cis-acting element CLE0 mediates induction signals in T cells and is recognized by factors related to AP1 and NFAT.

Expression of the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene in T cells is activated by the combination of phorbol ester (phorbol myristate acetate) and calcium ionophore (A23187), which mimic antigen stimulation through the T-cell receptor. We have previously shown that a fragment containing bp -95 to +27 of the mouse GM-CSF promoter can confer inducibility to reporter genes in the human Jurkat T-cell line. Here we use an in vitro transcription system to demonstrate that a cis-acting element (positions -54 to -40), referred to as CLE0, is a target for the induction signals. We observed induction with templates containing intact CLE0 but not with templates with deleted or mutated CLE0. We also observed that two distinct signals were required for the stimulation through CLE0, since only extracts from cells treated with both phorbol myristate acetate and A23187 supported optimal induction. Stimulation probably was mediated by CLE0-binding proteins because depletion of these proteins specifically reduced GM-CSF transcription. One of the binding factors possessed biochemical and immunological features identical to those of the transcription factor AP1. Another factor resembled the T-cell-specific factor NFAT. The characteristics of these two factors are consistent with their involvement in GM-CSF induction. The presence of CLE0-like elements in the promoters of interleukin-3 (IL-3), IL-4, IL-5, GM-CSF, and NFAT sites in the IL-2 promoter suggests that the factors we detected, or related factors that recognize these sites, may account for the coordinate induction of these genes during T-cell activation.

Animals↗
PubMed1993

[A new lupin alkaloid, (-)-leontalbinine N-oxide, in Sophora flavescens var. angustifolia seeds and its synthesis by biomimetic transformation from (+)-matrine N-oxide].

The possibility of the biomimetic transformation of (+)-matrine N-oxide, a main alkaloid in Sophora flavescens var. angustifolia, under various oxidative conditions was examined by the use of several metallic ions. When (+)-matrine N-oxide was warmed with FeSO4, or Fe(COOH)2 in MeOH-H2O at 40 degrees C, (-)-7, 11-didehydromatrine [(-)-leontalbinine], a minor alkaloid in the same plant, was obtained along with (+)-matrine. This selective formation of (-)-leontalbinine seems to be specific to the reaction of (+)-matrine N-oxide with ferrous reagents. In addition, the structure of the newly isolated minor lupin alkaloid from the seeds of S. flavescens. was determined as (-)-leontalbinine N-oxide from its spectral comparison with the authentic sample.

Alkaloids↗
PubMed1993

[Effects of protease inhibitors and protein synthesis inhibitors on cartilage tissue-dependent bone resorption].

We studied bone resorption of fetal rat femora in association with cartilage tissue. Some protease inhibitors, e.g., E-64, pepstatin A, phosphoramidon, amastatin, bestatin, foroxymithine, did not influence the bone resorption, but some serine protease inhibitors such as PMSF, TLCK, TPCK and elastatinal inhibited the bone resorption at 10(-5) M, 10(-4) M, 10(-4) M, 10(-4) M, respectively. A conditioned medium, obtained from cartilage tissue-cultured medium in the presence of 10(-4) M TPCK, which was then excluded from the medium by dialysis after the culture, stimulated the bone resorption. Cycloheximide (0.1 to 10 micrograms/ml) and puromycin (0.3 to 30 micrograms/ml) inhibited the cartilage tissue-dependent bone resorption. A A transient treatment of the femora with cycloheximide (3 micrograms/ml) for a day inhibited the bone resorption, but after the treatment, in the absence of cycloheximide, the femora gradually recovered the bone-resorbing activity. The conditioned medium, obtained from cartilage tissue-cultured medium in the presence of cycloheximide (3 micrograms/ml), which was then excluded from the medium by dialysis after the culture, failed to influence the bone resorption. These findings collectively suggest that cartilage tissue produces a bone resorption-stimulating factor(s) which is a serine protease or contains the protein as an inactive, latent form and then a certain serine protease converts it to an active form.

Animals↗
PubMed1993

Analysis of the site on a TNF-alpha molecule which affects type II TNF receptor binding in human cells.

The epitope region on the TNF-alpha molecule recognized by monoclonal antibody (mAb) 3-D-6, which neutralizes the cytotoxic activity on murine LM cells, has been determined as Gly24-Gln-Leu-Gln-Trp-Leu-Asn-Arg31. To examine whether this region participates in TNF receptor binding in human cell lines, four kinds of TNF-alpha mutants (Gln25 --> Glu, Gln27 --> Glu, Leu29 --> Val, and Arg31 --> Ser) were prepared using site-directed mutagenesis. One mutant, mRS31, which has a nonconserative mutation at position 31 (Arg --> Ser), showed markedly reduced binding in U-937 cells and in HL-60 cells compared with the wild-type recombinant TNF-alpha (rTNF-alpha). These two cell lines have been reported to have both type I and type II TNF receptors. mRS31 also showed reduced cytotoxicity on U-937 cells. Another mutant, mLV29, which has a conservative mutation at position 29 (Leu --> Val), showed, to a lesser extent, reduced binding in U-937 cells and HL-60 cells and reduced cytotoxic activity in U-937 cells. However, all four TNF-alpha mutants showed a similar binding in HEp-2 cells and in HeLa cells, which have been reported to have only the type I TNF receptor. These results suggest that Leu29 may be involved in direct contact with the type II receptor and that the nonconservative mutation at position 31 may induce a local conformational change in the site involved in type II TNF receptor binding.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

[Evaluation of bronchoalveolar lavage fluid in patients with B-cell lymphoma before and after COP-BLAM therapy].

In order to elucidate focal immunity of the lung before and after treatment of malignant lymphoma, evaluation was made of peripheral blood (PB) and bronchoalveolar lavage fluid (BALF) before and after COP-BLAM therapy. Ten patients with untreated B cell lymphoma without any abnormal shadow in the lung fields were studied. After treatment, slight increases in the total cell counts and macrophages in BALF were observed. In patients with pulmonary complications after treatment, the CD4/CD8 ratio in PB did not change after treatment, but it did change in BALF after treatment in patients with lung disease. According to 2-color analysis, CD4+CD45RA+ cells and CD4+HLA-DR+ cells were lower in BALF before treatment in patients with lung disease, suggesting some relationship with lung complications. The CD4/CD8 ratio of lymphocytes within BALF increased after COP-BLAM therapy, probably owing to NHL itself or to chemotherapy.

Administration, Oral↗
PubMed1993

[Two autopsy cases of sporadic amyotrophic lateral sclerosis with 20-year-clinical course without respirators].

The present paper concerns the clinicopathological study of two patients with sporadic amyotrophic lateral sclerosis (ALS) with 21 or 22 years' clinical course without respirators. The two cases developed marked upper motor neuron signs and continually progressive paralysis. Involvement of the facial and bulbar muscles remained fairly mild. At autopsy, the anterior horns showed marked loss of motor neurons associated with numerous reactive astrocytes. On the other hand, the motor cortex and the pyramidal tract showed diminution of Betz cells and large myelinated fibers but no positive materials by fat stain. In addition, the anterolateral funiculi of the spinal cords revealed widespread myelin pallor. One of the case showed intracytoplasmic eosinophilic inclusions in some neurons of the medullary reticular formation. Recent articles have reported several rapidly progressive ALS patients who developed ophthalmoplegia, while on respirators, and widespread degeneration in the CNS. By contrast, our extremely slowly progressive ALS patients developed alterations confined to upper and lower motor neurons. There may exist some diversities in ALS.

Aged↗
PubMed1993

[Studies on the botulinum therapy for esotropia improvement of retinal correspondence].

When botulinum therapy was used for esotropia with abnormal retinal correspondence, the esotropia improved effectively and binocular function recovered. Transient overcorrected deviation appeared in 92% of different cases of retinal correspondence. Patients without binocular function and abnormal retinal correspondence of various types were the subjects of this study. There were 18 congenital esotropes and 12 acquired esotropes. Before treatment, there was normal retinal correspondence > abnormal retinal correspondence (NRC > ARC) in 5 cases, abnormal retinal correspondence > abnormal retinal correspondence (ARC > NRC) in 8 cases, abnormal retinal correspondence (ARC) in 16 cases, and lack of retinal correspondence (LRC) in 1 case and the binocular function was incomplete in all cases. Botulinum toxin (0.25-0.5 U) injected into the medial rectus muscles showed hypertonic action. The dose was adjusted according to the deviation angle. We found some changes in retinal correspondence caused by the botulinum therapy in 24 of the 30 patients (80%). Of these there was NRC in 6, NRC > ARC in 11, and ARC > NRC in 7. Secondary esotropia was found in 92% of the 24 cases. We believe that improvement of retinal correspondence is due to suppression of anomalous retinal areas with the change of the overcorrected deviation after the usual visual direction disappears. Our results suggest that normal retinal correspondence has a relatively wide range of correspondence area.

Adolescent↗
PubMed1993

[A case of B cell lymphoma with negative findings in both chest X-ray and CT images, but lesions of the bronchial mucosa detected on bronchoscopy].

A 68-year-old woman presented to our hospital on January 7, 1992 with swelling of a right cervical lymph node as the chief complaint. After biopsy of the cervical lymph node, non-Hodgkin's lymphoma was diagnosed (diffuse medium cell type, B cell) and she was hospitalized on January 10. Except for the enlargement of the right cervical lymph node noted at the time of hospitalization, no abnormal findings on examination or in chest X-ray and CT scan were noted. However, at bronchoscopy rubor and swelling of the mucosa of the right second carina and the bifurcation between the left upper division and the lingular bronchus were noted, and biopsy was therefore performed. The histologic appearance of the biopsy tissue was similar to that of the lymph node, showing infiltration by malignant lymphoma. The tumor was diagnosed to be stage IIA of the Ann Arbor classification, and COP-BLAM therapy was commenced on January 15. On January 21, the cervical lymph node was no langer present. At bronchoscopy performed on January 25, the abnormal portion of the bronchi had disappeared, and no infiltration was observed in the biopsied specimen. There have been some reports describing lesions within the bronchi in cases of malignant lymphoma. However, there have been few cases in which no abnormalities were found in the chest X-ray and diagnosis was made by bronchoscopy. Thus, it seems to be useful and important to perform bronchoscopy in order to determine the stage of malignant lymphoma.

Aged↗
PubMed1993

HTLV-I encoded Tax in association with NF-kappa B precursor p105 enhances nuclear localization of NF-kappa B p50 and p65 in transfected cells.

NF-kappa B is a heterodimeric protein composed of two subunits, p50 and p65, and is sequestered in the cytoplasm as an inactive form through the association with an inhibitory protein, I kappa B. In the present study, the effect of HTLV-I encoded Tax on the exogenously expressed NF-kappa B p105, which encodes a precursor of p50, was investigated using a COS-7 expression system. When p105 was expressed in COS-7 cells, the precursor p105 and the processed p50 were retained in the cytosolic fraction by associating each other, and p50 was not detected in the nuclear fraction. In the cells co-expressing p105 and Tax, the p50/p105 ratio in the cytosolic fraction reduced with an induction of p50 in the nuclear fraction, which gave rise to a significant increase in NF-kappa B binding activity. Enhancement of NF-kappa B binding activity was not observed by adenovirus encoded E1A and bovine papilloma virus encoded E2, and correlated well with the ability of Tax to associate with p105. When p105 delta X which lacks the repeats of the ankyrin motif was expressed in this system, p105 delta X and processed p50 were detected in the nuclear fraction and p50/p105 delta X ratio was not affected by co-expression with Tax. In the same expression system, exogenously expressed NF-kappa B p65 was retained in the cytoplasm by p105 and further expression of Tax allowed entry of p65 in the nucleus. These results suggest that, in this model system, p105 acts as an I kappa B to sequester p50 and p65 in the cytoplasm and that Tax by inhibiting I kappa B activity of p105, enhances nuclear localization of p50 and p65. These findings raise a possibility for a novel mechanism for the induction of NF-kappa B in the nucleus by Tax.

Amino Acid Sequence↗
PubMed1993

[Bulky mediastinal malignant lymphoma].

The efficacy of treatment of 19 patients with malignant lymphoma presenting with mediastinal tumor was evaluated. They included 7 patients with Hodgkin's disease and 12 with non-Hodgkin's lymphoma (NHL). Numbers of patients with stage I, II, III and IV disease according to Ann-Arbor's classification were 6, 4, 3 and 6, respectively. Stage I patients were treated with CHOP therapy after radiotherapy (RT). Stage II and III patients were treated with RT after COP-BLAM chemotherapy. Stage IV patients were treated with COP-BLAM III regimen. Complete remission was achieved in 16 of 19 patients (84.2%), and partial remission in 2 (10.5%). All patients with Hodgkin's disease and 9 (75%) with NHL attained complete remission. All patients in stage I to III and 3 (50%) in stage IV achieved complete remission. Overall median survival was 66 months. The incidence of bone marrow involvement and bulky mass was significantly different between stage I.II and stage III.IV patients (p < 0.05). These results indicate that combination treatment with RT and chemotherapy with regimens including adriamycin was effective in patients with malignant lymphoma presenting with mediastinal tumor, especially in those without bone marrow infiltration and bulky mass.

Combined Modality Therapy↗