Biomedical subjects

Hiroshi Hara

Publications and source records attributed to Hiroshi Hara.

At least 19 recordsLinked to original sources

PubMed2003

Hybrid cell-gene therapy for pulmonary hypertension based on phagocytosing action of endothelial progenitor cells.

BACKGROUND: Circulating endothelial progenitor cells (EPCs) migrate to injured vascular endothelium and differentiate into mature endothelial cells. We investigated whether transplantation of vasodilator gene-transduced EPCs ameliorates monocrotaline (MCT)-induced pulmonary hypertension in rats. METHODS AND RESULTS: We obtained EPCs from cultured human umbilical cord blood mononuclear cells and constructed plasmid DNA of adrenomedullin (AM), a potent vasodilator peptide. We used cationic gelatin to produce ionically linked DNA-gelatin complexes. Interestingly, EPCs phagocytosed plasmid DNA-gelatin complexes, which allowed nonviral, highly efficient gene transfer into EPCs. Intravenously administered EPCs were incorporated into the pulmonary vasculature of immunodeficient nude rats given MCT. Transplantation of EPCs alone modestly attenuated MCT-induced pulmonary hypertension (16% decrease in pulmonary vascular resistance). Furthermore, transplantation of AM DNA-transduced EPCs markedly ameliorated pulmonary hypertension in MCT rats (39% decrease in pulmonary vascular resistance). MCT rats transplanted with AM-expressing EPCs had a significantly higher survival rate than those given culture medium or EPCs alone. CONCLUSIONS: Umbilical cord blood-derived EPCs had a phagocytosing action that allowed nonviral, highly efficient gene transfer into EPCs. Transplantation of AM gene-transduced EPCs caused significantly greater improvement in pulmonary hypertension in MCT rats than transplantation of EPCs alone. Thus, a novel hybrid cell-gene therapy based on the phagocytosing action of EPCs may be a new therapeutic strategy for the treatment of pulmonary hypertension.

Adrenomedullin↗

PubMed2003

Ingestion of water-soluble soybean fiber prevents osteopenia and hypercholesterolemia induced by ovariectomy in rats.

This study examined the effects of feeding water-soluble soybean fiber (WSSF), a highly fermentable dietary fiber with low viscosity, on intestinal calcium (Ca) absorption, bone mineral content, and serum total cholesterol levels using female Sprague-Dawley rats (5 weeks old) with or without ovariectomy (OVX). The rats in each group were fed a WSSF (50 g/kg of diet) or WSSF-free diet for 4 weeks. Ca absorption was higher in OVX rats fed the WSSF diet than in OVX rats fed the WSSF-free diet. Femoral Ca content in both sham and OVX rats fed the WSSF diet was higher than that in rats fed the WSSF-free diet. The serum total cholesterol levels were elevated after OVX compared with that in the sham rats, and this elevation was prevented by the WSSF diet. In conclusion, ingestion of WSSF prevented osteopenia and hypercholesterolemia induced by ovariectomy in rats.

Animals↗

PubMed2003

Long-term survival following treatment with antineoplastons for colon cancer with unresectable multiple liver metastases: report of a case.

We report a case of survival for nearly 8 years after treatment of unresectable multiple liver metastases from colon cancer, using microwave ablation and the nontoxic antitumor agent, the antineoplastons. A 72-year-old man diagnosed with adenocarcinoma of the ascending colon and 14 bilateral liver metastases underwent a right hemicolectomy combined with microwave ablation of six metastatic liver tumors. We also decided to give antineoplastons to inhibit metastatic tumor growth and recurrence. Antineoplaston A10 was given intravenously, followed by oral antineoplaston AS2-1. Computed tomography scans done 1 and 4 years after the initial diagnosis showed recurrent tumors in S(4) and S(7), respectively. The patient underwent a second and a third microwave ablation of the recurrent tumors, and has survived for nearly 8 years without suffering any serious adverse effects. He is currently free from cancer. This case report demonstrates the potential effectiveness of the nontoxic antitumor agent, the antineoplastons, for controlling liver metastases from colon cancer.

Adenocarcinoma↗

PubMed2003

Idiopathic interstitial pneumonia following stem cell transplantation.

Idiopathic interstitial pneumonia (IIP) can occur after stem cell transplantation, but the aetiology is unknown. Based on the association between angiitis syndrome and Helicobacter pylori infection, we identified possible risk factors common to these two conditions. Among 83 patients who underwent stem cell transplantation, four developed IIP. We elucidated various parameters and clinical features in four patients with IIP and 79 patients without, after allogeneic stem cell transplantation. In all four patients, (1) the conditioning regimen induced total body irradiation, (2) serological reactivation of cytomegalovirus and/or human herpesvirus-6 preceded the onset of IIP, (3) their human leucocyte antigen types were among those suspected to increase susceptibility to angiitis syndrome, (4) serum anti-H. pylori antibody was positive before conditioning and remained positive throughout the post-transplantation course, (5) inflammatory cytokines (interleukin-6, 8 and 12) were increased during the period of leucocyte recovery after transplantation and (6) the levels of intercellular adhesion molecule-1, thrombomodulin and plasminogen activator inhibitor-1 were increased at the onset of IIP. These findings suggest the possibility that angiitis syndrome and H. pylori infection are involved in the pathogenesis of post-transplantation IIP.

Adult↗

PubMed2003

Analysis of natural killer (NK) cell activity and adhesion molecules on NK cells from umbilical cord blood.

The activity of natural killer (NK) cells in human umbilical cord blood (CB) has been reported to be low, compared with that in adult peripheral blood (PB) in vitro. To examine the cause of this, after dividing the CD56+/CD3- cells in CB and PB into CD56bright and CD56dim NK cells, the NK cell activities and the expression of various surface antigens were assayed for each fraction. The NK cell activity of CD56dim NK cells in CB was significantly lower than that in PB (P = 0.0003), whereas, there was no significant difference between the NK cell activity of CD56bright NK cells in PB and CB. The expression levels of adhesion molecules (CD2, CD11a, CD18, DNAX accessory molecule-1), CD16, and CD57 for CD56dim NK cells in CB were significantly lower than those in PB, and approximately one-third of CB CD56dim NK cells were capable of forming conjugates with K562 cells, compared with PB CD56dim NK cells. Furthermore, the inhibition of both the NK cell activities and binding of CD56dim NK cells in PB and CB by monoclonal antibody against each of these adhesion molecules suggests that they play an important role in NK cell activity. These findings show that the low NK cell activity in CB is caused by the low NK cell activity of CD56dim NK cells and that the low expression level of adhesion molecules on CB CD56dim NK cells may contribute to this low NK cell activity.

Antibodies, Monoclonal↗

PubMed2003

Overexpression of S-adenosylmethionine decarboxylase (SAMDC) in Xenopus embryos activates maternal program of apoptosis as a "fail-safe" mechanism of early embryogenesis.

In Xenopus, injection of S-adenosylmethionine decarboxylase (SAMDC) mRNA into fertilized eggs or 2-cell stage embryos induces massive cell dissociation and embryo-lysis at the early gastrula stage due to activation of the maternal program of apoptosis. We injected SAMDC mRNA into only one of the animal side blastomeres of embryos at different stages of cleavage, and examined the timing of the onset of the apoptotic reaction. In the injection at 4- and 8-cell stages, a considerable number of embryos developed into tadpoles and in the injection at 16- and 32-cell stages, all the embryos became tadpoles, although tadpoles obtained were sometimes abnormal. However, using GFP as a lineage tracer, we found that descendant cells of the blastomere injected with SAMDC mRNA at 8- to 32-cell stages are confined within the blastocoel at the early gastrula stage and undergo apoptotic cell death within the blastocoel, in spite of the continued development of the injected embryos. These results indicate that cells overexpressed with SAMDC undergo apoptotic cell death consistently at the early gastrula stage, irrespective of the timing of the mRNA injection. We assume that apoptosis is executed in Xenopus early gastrulae as a "fail-safe" mechanism to eliminate physiologically-severely damaged cells to save the rest of the embryo.

Adenosylmethionine Decarboxylase↗

PubMed2003

Allogeneic hematopoietic stem cell transplantation.

More than 30 years have passed since the first clinical application of allogeneic bone marrow transplantation to treat hematological diseases. In recent years, the availability of peripheral blood and cord blood as additional sources of stem cells other than bone marrow has expanded the applicability of hematopoietic stem cell transplantation. In addition to differences in stem cell content, immune cells in the grafts from the three sources are different in quality and quantity. As a consequence, transplants from different sources have different kinetics of hematological recovery. Stem cell sources also influence risks for developing graft-versus-host disease. In this paper, we review recently reported results of thus diversified allogeneic hematopoietic, stem cell transplantation.

Adult↗

PubMed2003

Lymphatic absorption of plasmalogen in rats.

Plasmalogen is a subclass of phospholipids that is widely distributed in man and animals. Many physiological roles have been proposed for this lipid; however, there have been no reports on the intestinal absorption of plasmalogen. In the present study, we examined lymphatic absorption of plasmalogen after the duodenal infusion of emulsified brain phospholipids (BPL) containing plasmalogen (22 mol % of total phospholipids) and soyabean lecithin (SPL) (100 g emulsified phospholipid/l). Male Wistar rats with implanted cannulas in the mesenteric lymph duct and the duodenum were kept in a Bollman-type restraining cage, and were infused the emulsion after 1 d recovery with duodenal infusion of a glucose-NaCl solution. Lymphatic plasmalogen output was increased at 2-4 h after the switch to BPL emulsion, and peaked at 4-6 h. However, no increases were observed after SPL infusion. Lymphatic recovery of plasmalogen for 8 h was 198 nmol, which was 0.22 mol % of the total plasmalogen disappeared from the intestine. We did not detect any increases in long-chain fatty aldehydes, which are the degradation product of plasmalogen, either in the blood or the small intestine. We conclude that a small percentage but a significant amount of the plasmalogen was absorbed into the lymph.

Animals↗

PubMed2003

Enteral administration of soybean lecithin enhanced lymphatic absorption of triacylglycerol in rats.

As the physiological roles of dietary lecithin have not yet been clearly defined, we examined the effects of lecithin on lipid absorption in male Wistar rats with a mesenteric lymph cannula. Lymphatic absorption was observed after the infusion of 1 ml emulsion containing 100 mg test oil emulsified with sodium taurocholate (10 g/l) in three separate experiments. Test oils (100 mg) were: soyabean oil (triacylglycerol (TG) source, SO) and soyabean oil+lecithin (75 mg soyabean oil+25 mg lecithin, LE) in Expt 1; SO, LE or soyabean oil+lysolecithin (75 mg soyabean oil plus 25 mg lysolecithin, LY) in Expt 2; hydrolysed soyabean oil (HSO) or HSO+lysolecithin (75 mg HSO+25 mg lysolecithin, HLY) in Expt 3. After LE and LY infusions, lymph flow and the lymphatic output of TG was higher than after SO infusion at 0-30 min and 0-90 min respectively (Expts 1 and 2). Lecithin-induced increases in lymph TG output remained constant when HSO was infused (Expt 3). There were no differences in the TG:phospholipid ratio in the lymph after infusion among the groups; nevertheless, the lymphatic output of TG was much higher after infusion with LE than with SO. Fatty acid was released more efficiently from SO than from LE and LY by in vitro digestion with rat bile-pancreatic juice. These present results demonstrate that a TG emulsion containing soyabean lecithin or its hydrolysates promote lymphatic TG output and suggest that the increases in TG absorption do not depend on TG digestion.

Animals↗

PubMed2003

Establishment of mouse embryonic fibroblast cell lines that promote ex vivo expansion of human cord blood CD34+ hematopoietic progenitors.

The development of culture systems that facilitate ex vivo maintenance and expansion of transplantable hematopoietic progenitor cells (HPC) is vital to stem cell transplantation. The use of a monolayer of stromal cells on which to grow HPC in direct contact allows high efficiency ex vivo expansion of HPC. Here, we report an establishment of three murine embryonic fibroblast stromal cell lines from adherent cells of day-12 mouse embryos. Among them, HYMEQ-5 was most efficient in supporting long-term maintenance of human umbilical cord blood (CB) CD34(+) cells. Human CB CD34(+) cells cultured on HYMEQ-5 in the presence of stem cell factor (SCF), thrombopoietin, and flk-ligand (FL) showed high expansion of CD34(+)CD38(-) cells and highly proliferative potential-colony forming cells (HPP-CFC). Direct cell-to-cell contact between CD34(+) cells and HYMEQ-5 was important for this expansion. RT-PCR analysis showed that HYMEQ-5 produced FL, SCF, interleukin-6, and macrophage colony-stimulating factor (M-CSF). Expanded CB CD34(+) cells efficiently reconstituted hematopoiesis in nonobese diabetic/severe combined immunodeficient disease (NOD/SCID) mice. These findings suggest that HYMEQ-5 provides a milieu that supports long-term human hematopoiesis as well as ex vivo expansion of human CB CD34(+) HPC. This cell line may facilitate elucidation of the mechanism of cellular interactions between HPC and stromal cells.

Animals↗

PubMed2003

Soybean beta-conglycinin peptone suppresses food intake and gastric emptying by increasing plasma cholecystokinin levels in rats.

Cholecystokinin (CCK) is an important physiologic mediator that regulates satiety and gastric emptying. We demonstrated previously that soybean peptone acts directly on rat small intestinal mucosal cells to stimulate CCK release. In the present study, we examined the effects of beta-conglycinin, a major component of soy protein, and its peptone on food intake and gastric emptying after an intraduodenal infusion of beta-conglycinin peptone in relation to CCK release and interaction with the mucosal cell membrane. Intraduodenal infusion of beta-conglycinin peptone inhibited food intake in a dose-dependent manner, but that of whole soy peptone or camostat did not. The suppression of food intake by beta-conglycinin peptone was abolished by an intravenous injection of devazepide, a selective peripheral CCK receptor antagonist. The beta-conglycinin peptone infusion strongly suppressed gastric emptying with marked increases in portal CCK levels. We also observed that the beta-conglycinin peptone dose dependently and more potently stimulated CCK release from isolated dispersed mucosal cells of the rat jejunum than did beta-conglycinin itself. This stimulation corresponded to the binding activity of the peptide or protein to solubilized components of the rat jejunum membrane as evaluated by surface plasmon biosensor. These results indicate that beta-conglycinin peptone suppresses food intake, and this effect may be due to beta-conglycinin peptone in the lumen stimulating endogenous CCK release with direct acceptance to the intestinal cells.

Animals↗

PubMed2003

Ingestion of water-soluble soybean fiber prevents gastrectomy-induced iron malabsorption, anemia and impairment of voluntary running exercise performance in rats.

We examined the effects of feeding water-soluble soybean fiber (WSSF), a highly fermentable dietary fiber, on gastrectomy-induced iron malabsorption, anemia and impairment of exercise performance in rats in two separate experiments. The study was designed as a 2 x 2 factorial arrangement with operation (total gastrectomy) and diet (WSSF) under sedentary (Experiment 1) and exercised (Experiment 2) conditions. In Experiment 1, gastrectomy reduced net iron absorption, hemoglobin concentration, hematocrit and hemoglobin regeneration efficiency (P < 0.01). However, in rats fed a WSSF diet (50 g/kg diet), iron absorption and the hematological variables of the gastrectomized rats were comparable to those in the sham-operated rats, demonstrating that ingestion of WSSF promotes iron absorption and prevents anemia after gastrectomy. Feeding WSSF increased pools of organic acids and soluble iron in cecal contents and decreased the pH of the cecal contents (P < 0.001). Of the many cecal variables measured, net iron absorption in gastrectomized rats was most closely correlated (r = 0.614, P < 0.01) with the short-chain fatty acid pool in the cecum. Cecal fermentation of WSSF may contribute to improvements in gastrectomy-induced nutritional defects. In Experiment 2, we examined voluntary running exercise performance in totally gastrectomized rats fed diets with or without WSSF. Total gastrectomy severely impaired running performance (P < 0.001), and WSSF feeding largely restored the lowered performance. We conclude that feeding WSSF improves anemia and impaired voluntary running performance in totally gastrectomized rats.

Anemia, Iron-Deficiency↗

PubMed2003

The addition of soybean phosphatidylcholine to triglyceride increases suppressive effects on food intake and gastric emptying in rats.

The physiologic roles of dietary lecithin have not yet been clearly defined. We examined the effects of soybean lecithin on gastric emptying (Experiments 1 and 2) and food intake (Experiment 3) in rats. Male Wistar rats were fed 2 g of a 20 g lipid/100 g diet containing various levels of lecithin after 24 h of food deprivation; gastric contents were collected 3 h after feeding (Experiment 1). In Experiment 2, the effects of lecithin and a CCK-A receptor antagonist on gastric emptying were examined using a modified phenol red recovery technique. In Experiment 3, their effects on food intake were examined after an intraduodenal infusion of an oil emulsion containing 50 mg soybean oil (SO) or SO partially replaced by lecithin (14-50%). Gastric emptying rates of the lipid and protein in the test diet (Experiment 1) or of phenol red (Experiment 2) were lower in the groups administered lecithin. Food intake for 60 min was lower in rats infused with the oil emulsion containing lecithin (25, 50%) than in rats not administered lecithin. The suppressive effects of lecithin on gastric emptying and food intake were largely reduced by devazepide. These results demonstrate that oil containing lecithin inhibits gastric emptying and food intake, and the effects are associated in part with CCK release.

Animal Feed↗

PubMed2003

The soybean beta-conglycinin beta 51-63 fragment suppresses appetite by stimulating cholecystokinin release in rats.

We previously demonstrated that soybean beta-conglycinin peptone suppresses food intake and gastric emptying by direct action on rat small intestinal mucosal cells to stimulate cholecystokinin (CCK) release. The aim of the present study was to define the active fragment in beta-conglycinin by using synthetic peptides chosen from the sequence of three beta-conglycinin subunits. We selected the fragments that had multiple nonadjacent arginine residues, and investigated their ability to bind to components of the rat intestinal brush border membrane as well as to stimulate CCK release and appetite suppression. The fragment from 51 to 63 of the beta subunit (beta 51-63) had the strongest binding activity. Intraduodenal infusion of beta 51-63 inhibited food intake and markedly increased portal CCK concentration. The threshold concentration of beta 51-63 to affect food intake was 3 micro mol/L. The CCK-A receptor antagonist abolished the beta 51-63-induced suppression of food intake. Three types of smaller fragments of beta 51-63 (beta 51-59, beta 53-63 and beta 53-59) and two types of fragments similar to beta 51-63 in the beta-conglycinin alpha and alpha' subunits (alpha 212-224 and alpha' 230-240) had less binding ability than did beta 51-63. Model peptides constructed with arginine (R) and glycine (G), such as GRGRGRG, had strong binding affinity, but peptides containing a single R or RR did not. These results indicate that the beta-conglycinin beta 51-63 fragment is the bioactive appetite suppressant in beta-conglycinin, and multiple arginine residues in the fragment may be involved in this effect.

Animals↗

PubMed2003

Casein binds to the cell membrane and induces intracellular calcium signals in the enteroendocrine cell: a brief communication.

Dietary protein but not amino acids stimulates cholecystokinin (CCK) secretion in rat mucosal cells. However, the dietary protein sensory mechanisms and the intracellular signal pathway in the enteroendocrine cells have not yet been clarified. The relationship between dietary protein binding to cell membrane and intracellular calcium responses were examined in the CCK-producing enteroendocrine cell line STC-1. The binding of solubilized STC-1 cell membrane to proteins was analyzed using a surface plasmon resonance sensor. Intracellular calcium concentrations of STC-1 cell suspensions loaded with Fura-2 AM were measured using a spectrafluorophotometer system with continuous stirring. Intracellular calcium concentrations in STC-1 cells were increased by exposure to alpha-casein or casein sodium, but not to bovine serum albumin. Solubilized STC-1 membranes bound to alpha-casein and casein sodium but did not bind to bovine serum albumin. alpha-Casein demonstrated higher membrane binding and intracellular calcium stimulating activities than casein sodium. Thus, protein binding to the STC-1 cell membrane and intracellular calcium responses were correlated. Intracellular calcium responses to alpha-casein were suppressed by an L-type calcium channel blocker. These results suggest that casein, a dietary protein, binds to a putative receptor on the CCK-producing enteroendocrine cell membrane and elicits the subsequent intracellular calcium response via an L-type calcium channel.

Animals↗

PubMed2003

Absorptive activity of calcium in the isolated cecal epithelium adaptively increased by 2 week's feeding of difructose anhydride III in rats.

We compared net Ca absorption and Lucifer Yellow (LY), a paracellular passage dye, permeability in the epithelium isolated from the rat small intestine, cecum, and colon after feeding with control and difructose anhydride (DFA) III diets for 14 days using the Ussing chamber system. Feeding of DFA III increased net Ca transport and LY passage in the cecal but not in small intestinal or colonic epithelium. Ability of paracellular Ca passage via Tight-junction (TJ) in the cecum was changed adaptively by feeding of DFA III. Changes in microbial fermentation may affect the functional changes of Ca transport in cecal epithelium itself.

Animal Feed↗

PubMed2003

[Current status of reduced-intensity stem cell transplantation; survey in the Kinki area].

The status of reduced-intensity stem cell transplantation (RIST) in the Kinki area was investigated by questionnaires. We sent out questionnaires to 72 institutions and received 51 replies (72.2%). RIST was performed in 16 institutions (31.4%). A total of 91 cases were included of whom approximately 70% were non-remission or advanced hematological malignancies. Various conditioning regimens were used for RIST, most often consisting of fludarabine, busulfan and antithymocte globulin. Acute GVHD developed in 57% of all patients. Relapse or disease progression developed in 42.7% of evaluable patients. The overall survival rate was 54.6%, and 80% of low risk patients were alive at the time of analysis.

Adolescent↗

PubMed2003

Immortalization of bone marrow-derived human mesenchymal stem cells by removable simian virus 40T antigen gene: analysis of the ability to support expansion of cord blood hematopoietic progenitor cells.

Human marrow-derived mesenchymal stem cells (MSC), which have the potential to differentiate into mesenchymal tissues, such as bone, cartilage, adipose and bone marrow stroma, were transduced with a retroviral vector carrying the simian virus 40 large T antigen, hygromycin-resistant gene and herpes simplex virus thymidine kinase gene, that can be excised by Cre/loxP site-specific recombination. This resulted in establishment of an MSC cell line, HMSC-1, which retained original surface characteristics and differentiation potential, and exhibited a higher proliferative capacity than parental cells. HMSC-1 expressed mRNAs of BMP-4, Jagged-1, and SCF that are known to promote hematopoiesis. Human CB CD34+ hematopoietic progenitor cells (HPC) cultured on a layer of HMSC-1 cells showed high expansion of CD34+CD38- immature HPC, capable of reconstituting human hematopoiesis in non-obese diabetic/severe combined immunodeficient disease (NOD/SCID) mice. This cell line may be of value for developing strategies for ex vivo expansion of human HPC.

ADP-ribosyl Cyclase↗