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S Arai

Publications and source records attributed to S Arai.

At least 37 records · Page 2Linked to original sources
PubMed2001

Trehalose suppresses lipopolysaccharide-induced osteoclastogenesis bone marrow in mice.

We have previously shown that trehalose suppresses bone loss in ovariectomized (OVX) mice by way of inhibiting osteoclast differentiation in bone marrow. Also, trehalose inhibits the secretion of interleukin-6 in bone marrow cell cultures, resulting in a decrease in osteoclast formation. In this study, we examined the effect of trehalose on osteoclastogenesis using another model of bone resorption, namely lipopolysaccharide (LPS)-stimulated osteoclast induction. Mice were given trehalose (1g/kg) by gastric intubation for 5 consecutive days, and 24 hours later, 14 mg/kg of LPS was injected intraperitoneally. Trehalose significantly suppressed LPS-induced tumor necrosis factor (TNF)-alpha production after 90 min and decreased the number of osteoclasts in the bone marrow 48 hours after LPS injection. These results indicate that trehalose suppresses excessive osteoclastogenesis not only in OVX mice but also in a LPS-induced bone resorption mouse model and further suggest that the latter finding may be mediated at least in part through a decrease in TNF-alpha production.

Journal Article↗
PubMed2001

Identification and characterization of mouse bone marrow stromal cell lines immortalized by temperature-sensitive SV40 T antigen: supportive activity for osteoclast differentiation.

Osteoblasts are derived from mesenchymal/stromal cells in bone marrow, and gain the ability to support osteoclastogenesis during differentiation though the expression of receptor activator of NF-kappaB ligand (RANKL) and macrophage-colony stimulating factor (M-CSF). However, the properties (differentiation stage and expression of osteoblast marker genes) of stromal or osteoblastic cells that have the capacity to support osteoclast differentiation are unclear. Therefore, we sought to establish and characterize bone marrow-derived stromal cell lines (TSB) from temperature-sensitive SV40 T-antigen transgenic mice to define them at the clonal level. Of the 24 randomly selected cell lines, only 2 cell lines, TSB13 and TSB20, could support osteoclast differentiation in the presence of 1alpha,25(OH)(2)D(3). In both cell lines, RANKL mRNA was induced and osteoprotegerin (OPG) mRNA was decreased in response to treatment with 1alpha,25(OH)(2)D(3) for 2 days. Other RNA expression analyses of osteoblast-specific marker genes demonstrated the following characteristics of TSB13 and TSB20: (1) alkaline phosphatase (ALP) and type I collagen genes are expressed; (2) osteocalcin and osteopontin genes are expressed at low levels, and their expression levels are upregulated after induction of differentiation by a temperature shift from 33 degrees C to 37 degrees C, or 1alpha,25(OH)(2)D(3) treatment. Consequently, the long-term culture of TSB13 and TSB20 cell lines strongly stimulated osteocalcin expression and effectively induced calcified nodule formation in the presence of phosphate. The results suggest that the supportive cells for osteoclastogenesis are restricted to a specialized population of bone marrow stromal cells, and the high ratio of RANKL vs. OPG expression found in this population after 1alpha,25(OH)(2)D(3) treatment might be a general property of osteoclast-supporting cells.

Animals↗
PubMed2001

Mycophenolate mofetil for the prevention and treatment of graft-versus-host disease following stem cell transplantation: preliminary findings.

The therapeutic benefits of allogeneic stem cell transplantation in patients with hematologic disorders are limited by the significant morbidity and mortality of graft-versus-host disease (GVHD). Current agents for the prevention and treatment of GVHD have limited efficacy and often result in toxic side-effects. Mycophenolate mofetil (MMF) is a new immunosuppressant with a selective mechanism of action. When employed following solid organ transplantation, MMF reduces the incidence and severity of acute rejection episodes. By selectively targeting activated lymphocytes, the active metabolite of MMF, mycophenolic acid (MPA), appears to augment the actions of standard immunosuppressant agents without adding overlapping toxicities. Studies of combination regimens that include MMF report that this agent permits a dose reduction of cyclosporine, tacrolimus, or corticosteroid, without increasing the incidence of acute rejection in solid organ transplants. Reports on the efficacy of MMF following stem cell transplantation in animal studies were mixed. However, the use of a non-myeloablative conditioning regimen with a post-graft immunosuppressive regimen of MMF and cyclosporine was able to sustain stable mixed chimeras in 60% to 80% of dogs who received hematopoietic grafts from DLA-identical littermates. MMF has demonstrated activity in preliminary clinical trials for GVHD prophylaxis, and treatment of acute or chronic GVHD. Larger clinical trials are warranted to determine the optimum dose and route of MMF administration for GVHD, as well as the comparative safety and efficacy of MMF-containing regimens.

Animals↗
PubMed2001

Von Willebrand factor-cleaving protease activity and proteolysis of von Willebrand factor in bone marrow transplant-associated thrombotic microangiopathy.

INTRODUCTION: Thrombotic microangiopathy (TM) of the fulminant type occurring in patients following bone marrow transplant (BMT) has clinical manifestations that are similar to thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome, but the outcome is generally fatal despite conventional therapy. Idiopathic acquired TTP has been associated with IgG inhibitors to the cleaving protease of von Willebrand factor (vWF) in plasma. In this study, we investigated the role of the vWF protease and vWF proteolysis in the pathogenesis of BMT-associated TM of the fulminant type. METHODS: vWF antigen level, vWF multimeric pattern, and vWF metalloprotease activity were investigated in the plasma samples of six consecutive patients with acute BMT-associated TM. Histologic and immunohistochemical studies were also performed on autopsy kidney specimens from four of the patients. All six patients had the fulminant type of the disorder with a fatal outcome and none of the patients responded to plasma infusion. RESULTS: The vWF-cleaving protease activity in plasma was normal in all patients. However, analysis of the vWF multimeric pattern showed a decrease of high molecular weight multimers. The decrease of large multimers may be caused by vWF-platelet binding as well as shear enhanced proteolysis of vWF. In the four patients who had an autopsy, a pattern of arteriolar thrombosis, distinct from that of TTP, was detected in the kidneys. CONCLUSION: These findings suggest that BMT-associated TM of the fulminant type is a heterogeneous process and distinct from TTP in pathogenesis. Analysis of vWF protease and vWF multimeric distribution are valuable tools in making the distinction between BMT-associated TM and TTP.

ADAM Proteins↗
PubMed2001

Acholeplasma laidlawii up-regulates granulysin gene expression via transcription factor activator protein-1 in a human monocytic cell line, THP-1.

An antimicrobial protein granulysin is constitutively expressed in cytotoxic T lymphocytes (CTL) and natural killer (NK) cells. However, little is known about the precise regulatory mechanisms underlying granulysin gene expression. In this study, we examined the regulatory mechanisms underlying granulysin gene expression using a human monocytic cell line, THP-1, treated with Acholeplasma laidlawii. The level of granulysin mRNA expression in THP-1 cells was significantly augmented in response to stimulation with A. laidlawii. The transfection of reporter gene constructs into THP-1 cells indicated that DNA sequences between residues -329 and -239, relative to the transcriptional start site of the granulysin gene, are responsible for mediating gene induction. In addition, mutagenesis of a putative activator protein-1 (AP-1)-binding site between residues -277 and -271 in the granulysin promoter resulted in the reduction of granulysin promoter activity. Electrophoretic mobility shift assays (EMSA) demonstrated that nuclear extract prepared from A. laidlawii-treated THP-1 cells can generate specific binding to DNA oligonucleotides encompassing the AP-1-binding site, whereas unstimulated nuclear extract from the cells failed to do so. Furthermore, competition and supershift assays confirmed that A. laidlawii can induce the activation of AP-1. These results indicate that AP-1 dominantly participates in the regulation of inducible granulysin gene expression in THP-1 cells. Therefore, the finding of inducible granulysin gene expression by A. laidlawii suggests that inducible granulysin in macrophages may function as a protective weapon when microbial invasion occurs.

Acholeplasma laidlawii↗
PubMed2001

In situ high resolution electron microscopy/electron energy loss spectroscopy observation of wetting of a Si surface by molten Al.

Electron energy loss spectroscopy was used to observe the segregation of Al on a Si surface above the melting point of Al. A mixture of Al and Si particles was heated above the melting point of Al in a vacuum of 1 x 10(-5) Pa. The Si surface, which initially had been covered with an amorphous oxide layer before heating, became clean and atomically facetted when the Al melted. It was shown that the Si surface was segregated with Al.

Journal Article↗
PubMed2001

Angiogenesis and phenotypic alteration of alveolar capillary endothelium in areas of neoplastic cell spread in primary lung adenocarcinoma.

Normal alveolar capillary endothelium is quiescent in nature and displays anticoagulant thrombomodulin (TM) on its surface. The cytoplasms of these endothelial cells are ultrastructurally non-fenestrated type, and they barely express von Willebrand factor (vWf). Alveolar fibrosis is accompanied by a capillary endothelium reactive for vWf, and a loss of TM expression. In primary lung adenocarcinoma, neovascularization occurs in association with alveolar fibrosis. In order to study basic factors related to angiogenesis and phenotypic changes of the capillaries located in tumor-bearing alveolar walls, we examined 37 primary lung adenocarcinomas with electron microscopy and confocal laser scanning microscopy with antibodies for TM, vWf, vascular endothelial growth factor (VEGF), and its receptors (KDR and Flt-1), and proliferating markers (Ki-67/proliferating cell nuclear antigen). Tissues microdissected specifically from alveolar walls were used for reverse transcription-polymerase chain reaction (RT-PCR) to assess expressions of mRNA isoforms of VEGF and its receptors. New capillary branching was found by ultrastructural study in the alveolar walls in 12% of the patients. Nuclei of the capillary endothelial cells were reactive for proliferating cell markers. Endothelial fenestrae were developed in 65% of the patients, TM reactivity was lost in the alveolar capillaries, and their cell cytoplasms obtained a reactivity for vWf through a transitional mosaic-like distribution pattern of both antigens. Besides cytoplasmic VEGF expression in neoplastic cells, tumor-bearing alveolar walls showed significant expression of mRNA of VEGF165 and KDR. These findings imply that angiogenesis and phenotypic changes of the alveolar capillaries are closely related to a higher expression of tumor-associated VEGF165 and of KDR in the alveolar walls in primary lung adenocarcinoma.

Adenocarcinoma↗
PubMed2001

Aerogenous spread of primary lung adenocarcinoma induces ultrastructural remodeling of the alveolar capillary endothelium.

To determine whether pulmonary alveolar capillaries manifest ultrastructural remodeling at areas of neoplastic invasion of primary lung adenocarcinomas, we examined 17 well-differentiated adenocarcinomas of lung (2 bronchioloalveolar and 15 papillary adenocarcinomas) by electron microscopy. The expression of vascular endothelial growth factor (VEGF) and proliferating cell nuclear antigen (PCNA) was demonstrated by immunohistochemical stainings. VEGF messenger RNA (mRNA) isoforms were detected by reverse-transcription polymerase chain reaction (RT-PCR) in alveolar walls microdissected from normal and tumor-associated tissues. Cytoplasm of neoplastic cells expressed VEGF protein in all patients. Endothelial cell nuclei of alveolar capillaries showed positive reaction for PCNA. Alveolar capillary lumina were distended like venules, and some intercellular junctions remained open. The cytoplasm of the capillary endothelial cells was enlarged and developed numerous organelles such as Weibel-Palade bodies and vesiculovacuolar organelles, in contrast to marked attenuation in their normal counterpart. Capillary sprouting occurred from proper alveolar capillaries in 2 patients. Cytoplasmic segments became extremely attenuated and developed diaphragm-like fenestrae in 65% of the patients. A relatively higher expression of diffusable isoforms of VEGF mRNA was seen in the tumor-bearing alveolar walls than in normal walls. Expression of KDR (one of the VEGF receptors) mRNA in tumor exceeded that in normal tissues. These results suggest that diffusable isoforms of VEGF mRNA released from the neoplastic cells are deeply involved in the induction of growth activity of alveolar capillary endothelial cells as much as in the characterization of tumor-associated microvessels in primary lung adenocarcinomas.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed2001

Activation by 2-arachidonoylglycerol, an endogenous cannabinoid receptor ligand, of p42/44 mitogen-activated protein kinase in HL-60 cells.

2-Arachidonoylglycerol (2-AG), an endogenous cannabinoid receptor ligand, was shown to induce rapid phosphorylation of p42/44 mitogen-activated protein kinase (MAP kinase) in HL-60 cells. We confirmed that the enzyme activity of p42/44 MAP kinase in HL-60 cells was augmented markedly when the cells were stimulated with 2-AG. The addition of SR144528, a cannabinoid CB2 receptor-specific antagonist, to the cells prior to the addition of 2-AG abolished the response induced by 2-AG, indicating that the CB2 receptor is involved in the response. G protein G(i) or G(o) is also assumed to be involved, because pertussis toxin treatment of the cells nullified the response induced by 2-AG. CP55940 and anandamide also induced the activation of p42/44 MAP kinase, although the activation by anandamide was less pronounced than that by 2-AG or CP55940. These results suggest that 2-AG may play an important physiological role in this type of cell through the activation of the p42/44 MAP kinase cascade.

Arachidonic Acids↗
PubMed2001

Gonadotropin-releasing hormone in third ventricular cerebrospinal fluid of the heifer during the estrous cycle.

The release profile of GnRH in cerebrospinal fluid (CSF) and its correlation with LH in peripheral blood of ovary-intact heifers during the estrous cycle were investigated. A silicon catheter was placed into the third ventricle of six heifers using ultrasonography. During the mid-luteal phase, the heifers were injected with prostaglandin F(2alpha) to induce luteolysis. Surges of CSF GnRH (66.7 h after prostaglandin F(2alpha) administration) and peripheral LH (66.3 h) occurred simultaneously and were coincident with the onset of estrus (67.0 h). Duration of elevated GnRH concentration considerably overlapped with the estrous phase in each of the heifers. Mean pulse frequencies of both GnRH and LH were significantly higher during the proestrous and early luteal phases than during the mid-luteal phase, while mean concentration and pulse amplitude of both GnRH and LH were not different between these three phases. Of all the GnRH pulses identified, more than 80% were accompanied by an LH pulse during the proestrous and early luteal phases. However, the proportion of GnRH pulses that were coincident with an LH pulse during the mid-luteal phase decreased to 60%. The results clearly demonstrate that a dynamic (pulse) and longer-term (surge) changes of GnRH release into CSF are physiologically expressed during the estrous cycle in heifers, and the pattern of pulsatile GnRH secretion in heifers depends upon their estrous cycle.

Animals↗
PubMed2001

Role of furin in delivery of a CTL epitope of an anthrax toxin-fusion protein.

Anthrax toxin lethal factor (LF) in combination with anthrax toxin protective antigen (PA) was endocytosed and translocated to the cytosol of mammalian cells. Residues 1-255 of anthrax toxin lethal factor (LFn) was fused to a cytotoxic T lymphocyte (CTL) epitope of an influenza virus. For processing the toxins, PA must be cleaved into a 63-kDa fragment (PA63) by furin, which is a subtilisin-like processing endo-protease expressed by many eukaryotic cells. To test the ability of cells treated with the LFn fusion protein plus PA to deliver the epitope, CTL assay was performed. Two types of cell lines were identified, one was able to deliver CTL epitope while the other failed to efficiently deliver the epitope. To further elucidate the differences between these cells, the role of furin in these cells was examined. Disruption of the furin gene reduced its ability to deliver the CTL epitope. Furin expression in cells capable of efficiently delivering CTL epitope was quantitatively higher than in cells unable to deliver the epitope. The results suggest that furin plays a critical role in delivery of the CTL epitope of LFn fusion protein.

Animals↗
PubMed2001

Use of antiserum-coated latex particles for serotyping Streptococcus pneumoniae.

The Quellung reaction provides a standard means for serotyping Streptococcus pneumoniae, but it requires microscopic examination with skillful technique. We have developed an improved agglutination method with anti-rabbit IgG-coated latex particles, which are sensitized with pooled antisera for serotyping/serogrouping S. pneumoniae. Our method is as specific and sensitive as the Quellung test, and much easier to perform.

Animals↗
PubMed2001

In vitro activities of moxifloxacin and other fluoroquinolones against Mycoplasma pneumoniae.

A total of 105 isolates of Mycoplasma pneumoniae were evaluated for susceptibility to moxifloxacin, sparfloxacin, levofloxacin, and ciprofloxacin. Moxifloxacin, a newly synthesized compound, showed the greatest activity. The MICs and MBCs at which 50 and 90% of isolates were affected were 0.15 (MIC(50) and MBC(50)) and 0.3 microg/ml (MIC(90) and MBC(90)) respectively. The results indicate that moxifloxacin might be promising an antimycoplasmal agent.

Anti-Infective Agents↗
PubMed2001

Human babesiosis in Japan: epizootiologic survey of rodent reservoir and isolation of new type of Babesia microti-like parasite.

We have carried out epizootiologic surveys at various sites in Japan to investigate wild animals that serve as reservoirs for the agents of human babesiosis in the country. Small mammals comprising six species, Apodemus speciosus, Apodemus argenteus, Clethrionomys rufocanus, Eothenomys smithii, Crocidura dsinezumi, and Sorex unguiculatus, were trapped at various places, including Hokkaido, Chiba, Shiga, Hyogo, Shimane, and Tokushima Prefectures. Animals harboring Babesia microti-like parasites were detected in all six prefectures. Inoculation of their blood samples into hamsters gave rise to a total of 20 parasite isolates; 19 were from A. speciosus, and the other 1 was from C. rufocanus. Sequencing of the parasite small-subunit rRNA gene (rDNA) sequence revealed that 2 of the 20 isolates were classified as Kobe type because their rDNAs were identical to that of the Kobe strain (the strain from the Japanese index case). The other 18 isolates were classified as a new type, designated the Hobetsu type, because they all shared an identical rDNA sequence which differed significantly from both that of Kobe-type isolates and that of northeastern United States B. microti (U.S. type). The parasites with Kobe-, Hobetsu- and U.S.-type rDNAs were phylogenetically closely related to each other but clearly different from each other antigenically. The isolates from rodents were demonstrated to be infective for human erythrocytes by inoculation into SCID mice whose erythrocytes had been replaced with human erythrocytes. The results suggest that a new type of B. microti-like parasite, namely, the Hobetsu type, is the major one which is prevalent among Japanese wild rodents, that A. speciosus serves as a major reservoir for both Kobe- and Hobetsu-type B. microti-like parasites, and that C. rufocanus may also be an additional reservoir on Hokkaido Island.

Animals↗
PubMed2001

A mainstay of functional food science in Japan--history, present status, and future outlook.

The development of food science in the near future probably depends on the advance in functional food science, the concept of which was proposed first in Japan nearly 15 years ago. The new science has been internationally distributed and accepted as conceptually being beyond nutrition. In Japan, however, it traced a unique path of progress in the form of a product-driven rather than concept-driven science. Actually, a number of substances and products with potential for disease risk reduction rather than simply for health maintenance have been investigated for their body-modulating functions. Some of them have been applied in practice to the industrialization of functional foods in terms of "foods for specified health uses" legally defined by new legislation. A variety of sophisticated methods have been introduced as well, including the so-called "XYZ" evaluation system, database construction for assessment of the function, and even the DNA microarray technique. The Ministry of Agriculture, Forestry, and Fisheries (MAFF) and the Ministry of Health and Welfare (MHW) also commenced their scientific as well as political activity, with its spread to industries which almost simultaneously began to vigorously investigate functional food products for enlargement of the food market. With all of this as a background, the Japan Liaison of the International Union of Food Science and Technology (IUFoST) hold a function food science symposium on behalf of related scientific bodies including the Japan Section of the International Life Science Institute (ILSI). This paper is an overview compiled from 12 presentations made in the symposium, with the aim of internationally publicizing the activity of functional food science in Japan.

Animals↗
PubMed2001

Molecular cloning, characterization, and expression of wheat cystatins.

We cloned four kinds of cDNAs of wheat cystatins (WCs), WC1, WC2, WC3, and WC4, from the seed. They had 47-68% amino acid sequence similarities to other plant cystatins. WC1, WC2, and WC4 had 63-67% similalities to one another while 93% of amino acids were identical between WC1 and WC3. This suggested that WCI, WC2, and WC4 should be regarded as the isoforms of wheat cystatins. The mRNAs for WC1, WC2, and WC4 were all expressed in seed at an early stage of maturation and, after that, their quantities decreased gradually. However, each of the mRNAs was again expressed one day after the start of germination and the expression continued for the following five days. WC1 seemed to be expressed at a higher level than WC2 and WC4. Immunostaining for looking at site-specific expression of each WC demonstrated that both WC1 and WC4 existed in the aleuron layer and embryo, but in the endosperm the only existing species was WC1. Differences in mRNA level and tissue localization found for the WCs may suggest their differential physiological roles.

Amino Acid Sequence↗
PubMed2001

Chemical and nutritional properties of hypoallergenic wheat flour.

The chemical and nutritional properties were investigated of hypoallergenic wheat flour (HWF) prepared by the cellulase-actinase treatment. HWF was composed mainly of oligopeptides and free amino acids, and its average molecular weight was lower than 1,000. Feeding tests on rats showed that, with respect to the PER, GOT and GPT activities and other nutritional indices, the HWF diet was almost equivalent to the control diet which had been prepared from normal wheat flour (NWF). No abnormality was apparent in the main organs after the HWF diet had been fed for 3 weeks. The small intestinal absorption of the HWF diet was found normal by measuring the free amino acid concentration in the intestinal tract and in the portal vein plasma. These data suggest that the absorption of amino acids from the HWF diet was comparable with or more efficient than that from a simulated free amino acid diet.

Amino Acids↗