Biomedical subjects

Hiroshi Hara

Publications and source records attributed to Hiroshi Hara.

At least 19 recordsLinked to original sources

PubMed2004

Gastroprotective effect of red pigments in black chokeberry fruit (Aronia melanocarpa Elliot) on acute gastric hemorrhagic lesions in rats.

It has been reported that the fruits and leaves of berries such as the blackberry, raspberry, and strawberry contain a high level of scavenging activity for chemically generated active oxygen species. This study investigated the antioxidative activities of black chokeberry fruit (Aronia melanocarpa Elliot) both in vitro and in vivo using the DPPH stable radical and rats with ethanol-induced gastric injury, respectively. The red pigment fraction of the black chokeberry contained three main components, one of which was identified as cyanidin 3-O-beta-glucoside by HPLC analysis and (1)H NMR. The black chokeberry red pigment fraction scavenged >44% of DPPH radicals at a concentration of 25 microg/mL compared to the control solution. The black chokeberry extract and its hydrolysate administrated at 2 g/kg of body weight each had nearly the same protective effect as quercetin administrated at 100 mg/kg of body weight in suppressing the area of gastric mucosal damage caused by the subsequent application of ethanol to <30% compared to the control group. The black chokeberry red pigment fraction had a similarly significant protective effect on gastric mucosa in a dose-dependent manner when administered at 30-300 mg/kg of body weight, and the administration of 30 mg/kg of body weight could suppress ethanol-induced gastric mucosal damage by approximately 50% (ID(50) = 30 mg/kg of body weight).

Animals↗

PubMed2004

Hepatocyte growth factor preserves graft-versus-leukemia effect and T-cell reconstitution after marrow transplantation.

Graft-versus-host disease (GVHD) is a major complication of allogeneic bone marrow transplantation (BMT). When GVHD is controlled by T-cell-depleted grafts or immunosuppressants, BM transplant recipients often suffer from an increased rate of leukemic relapse and impaired reconstitution of immunity. Using a mouse BMT model, we investigated the effects of hepatocyte growth factor (HGF) gene transfection on the severity of GVHD, the graft-versus-leukemia effect, and the reconstitution of T cells after BMT. After HGF gene transfer, acute GVHD was reduced, while mature donor T-cell responses to host antigens were preserved, resulting in a significant improvement of leukemia-free survival. HGF gene transfer promoted regeneration of bone marrow-derived T cells and the responsiveness of these cells to alloantigens. Furthermore, HGF preserved the thymocyte phenotype and thymic stromal architecture in mice with GVHD. This suggested that HGF exerts a potent protective effect on the thymus, which in turn promotes reconstitution of bone marrow-derived T cells after allogeneic BMT. These results indicate that HGF gene transfection can reduce acute GVHD preserving the graft-versus-leukemia effect, while promoting thymic-dependent T-cell reconstitution after allogeneic BMT.

Animals↗

PubMed2004

Effect of FK506 on donor T-cell functions that are responsible for graft-versus-host disease and graft-versus-leukemia effect.

BACKGROUND: FK506 is a potent immunosuppressive agent that is used in human graft-versus-host disease (GvHD) prevention. However, the precise mechanisms for GvHD prevention and the effect on graft-versus-leukemia (GvL) activity are unknown. This study was undertaken to determine the effect of FK506, given at clinically relevant doses, on donor T-cell functions responsible for GvHD and GvL activity. METHODS: The effect of FK506 on GvHD prevention and GvL activity was investigated using a murine model of allogeneic bone-marrow transplantation in which mice were injected with a P815 leukemic cell line. The regulatory role of FK506 on donor T cells was tested by analysis of donor T-cell expansions in the spleen and donor anti-host T-cell proliferative and cytotoxic responses. mRNA expression of type 1 T helper (Th1), Fas ligand (L), and granzyme B were also evaluated in target organs of GvHD. RESULTS: FK506 significantly prolonged the survival of GvHD mice when given at the trough level of 17.6 ng/mL, whereas it also blocked GvL effect in P815-injected GvHD mice. FK506 reduced the expansion of donor CD8+ and, to a lesser extent, CD4+ T cells in the spleen and inhibited donor anti-host T-cell proliferative and cytotoxic responses. It also inhibited the induction of Th1, FasL, and granzyme B mRNA expression in target organs of GvHD. CONCLUSIONS: FK506 inhibits both GvHD and GvL activity when given at clinical doses by inhibiting donor T-cell expansion, donor anti-host T-cell reactivity, and Th1 immune responses.

Animals↗

PubMed2004

Indigestible disaccharides open tight junctions and enhance net calcium, magnesium, and zinc absorption in isolated rat small and large intestinal epithelium.

The effects of three indigestible disaccharides on net calcium (Ca), magnesium (Mg), and zinc (Zn) transport in isolated rat jejunal, ileal, cecal, and colonic epithelium were determined. Permeability of fluorescein isothiocynate-dextran-4 (FD4) and transepithelial electrical resistance (TEER), which vary according to tight junction (TJ) activity in the intestinal mucosa, were also determined. The addition of 1-100 mM melibiose, difructose anhydride (DFA) III, or DFA IV to the mucosal medium increased the net absorption of the three minerals and FD4 permeability, while decreasing TEER dose dependently in the four intestinal portions. Positive linear relations were found between the net transport of the three minerals and FD4 passage in all portions of the intestine, whereas negative linear relations were observed between net absorption of the three minerals and TEER. We concluded that the three indigestible saccharides directly affect the epithelial tissue and open TJs, thereby promoting Ca, Mg, and Zn absorption in the small and large intestine in vitro.

Animals↗

PubMed2004

Cardiolipin domains in Bacillus subtilis marburg membranes.

Recently, use of the cardiolipin (CL)-specific fluorescent dye 10-N-nonyl-acridine orange (NAO) revealed CL-rich domains in the Escherichia coli membrane (E. Mileykovskaya and W. Dowhan, J. Bacteriol. 182: 1172-1175, 2000). Staining of Bacillus subtilis cells with NAO showed that there were green fluorescence domains in the septal regions and at the poles. These fluorescence domains were scarcely detectable in exponentially growing cells of the clsA-disrupted mutant lacking detectable CL. In sporulating cells with a wild-type lipid composition, fluorescence domains were observed in the polar septa and on the engulfment and forespore membranes. Both in the clsA-disrupted mutant and in a mutant with disruptions in all three of the paralogous genes (clsA, ywjE, and ywiE) for CL synthase, these domains did not vanish but appeared later, after sporulation initiation. A red shift in the fluorescence due to stacking of two dye molecules and the lipid composition suggested that a small amount of CL was present in sporulating cells of the mutants. Mass spectrometry analyses revealed the presence of CL in these mutant cells. At a later stage during sporulation of the mutants the frequency of heat-resistant cells that could form colonies after heat treatment was lower. The frequency of sporulation of these cells at 24 h after sporulation initiation was 30 to 50% of the frequency of the wild type. These results indicate that CL-rich domains are present in the polar septal membrane and in the engulfment and forespore membranes during the sporulation phase even in a B. subtilis mutant with disruptions in all three paralogous genes, as well as in the membranes of the medial septa and at the poles during the exponential growth phase of wild-type cells. The results further suggest that the CL-rich domains in the polar septal membrane and engulfment and forespore membranes are involved in sporulation.

Acridine Orange↗

PubMed2004

Ingestion of raffinose promotes calcium absorption in the large intestine of rats.

We examined the effects of feeding raffinose on intestinal calcium absorption in ovariectomized rats by two separate experiments. In experiment 1, female Sprague-Dawley rats (6 wk old) were divided into two groups: sham operation and ovariectomy, and fed diets with or without raffinose (30 g/kg diet) for 4 wk. In experiment 2, ovariectomized rats with cecocolonectomy or transsection and reanastomosis (sham) were divided into two groups as in experiment 1 and fed the same diets for 3 wk. In experiment 1, calcium absorption was lower in the ovariectomized rats than in the sham rats but calcium absorption in rats fed the raffinose diet was higher than that in rats fed the raffinose-free diet. In experiment 2, increased calcium absorption in the raffinose group was abolished by cecocolonectomy. The impaired absorption in ovariectomized rats was restored by feeding raffinose. The large intestine is involved in the beneficial effects of raffinose.

Animals↗

PubMed2004

Reducing effect of ingesting tannic acid on the absorption of iron, but not of zinc, copper and manganese by rats.

Interest in the beneficial effects of polyphenols, including tannic acid (TA), is increasing, although, these compounds also have adverse effects; for example, on the absorption of iron (Fe), and possibly other trace minerals. We examined the effect of a graded dose of TA on the absorption of Fe and compared with that of zinc (Zn), copper (Cu) and manganese (Mn) in rats. We also investigated the effect of TA on cecal fermentation which plays a role in absorption. In Experiment 1, to set the optimum dose of Fe, male Sprague-Dawley rats (weighing 70-90 g) after acclimatization were fed with different levels of dietary Fe (5, 10, 20, 30 and 35 mg/kg). We observed that the hematocrit (Ht), serum Fe concentration and transferrin saturation (%) were each reduced in those rats fed less than 20 mg/kg Fe in a dose-dependent manner. In Experiment 2, the rats were fed with test diets containing the minimum required level of Fe, 30 mg/kg diet, with (5, 10, 15 and 20 g/kg diet) or without TA for a period of three weeks. Feeding a diet containing more than 10 g TA/kg diet, but not 5 g TA/kg diet, reduced the hemoglobin concentration (Hb), Ht and serum Fe concentration due to decreased Fe absorption. In contrast, the Zn, Cu and Mn absorption was not affected by TA feeding. It is also demonstrated that liver Fe, but not the Zn, Cu and Mn contents, were lower in the TA groups than in the TA-free control group. Feeding TA slightly decreased the pH value of the cecal contents with an increase in the major short-chain fatty acid pool. About 15% of the ingested TA were recovered in the feces of each TA-fed group. Our results demonstrate that more than 10 g TA/kg diet induced anemia by reducing the Fe absorption, although there was no effect on the absorption of other important trace minerals. Our findings suggest that the usual intake of polyphenols is relatively safe, but that a high intake by supplementation or by dietary habit of tannin affects only the Fe level.

Animals↗

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

Ingestion of plasmalogen markedly increased plasmalogen levels of blood plasma in rats.

Plasmalogens, a subclass of phospholipids, are widely distributed in human and animals, and are taken into the body as food. However, no data exist on the intestinal absorption or fate of ingested plasmalogen. Here, we determined whether dietary plasmalogen is absorbed and whether blood and tissue concentrations increased in normal male Wistar rats by using four separate experiments. Phospholipids containing more than 20 wt% of plasmalogen extracted from the bovine brain were incorporated into test diets (10-15 wt%). In experiment 1, we estimated the absorption rate by measuring the plasmalogen vinyl ether bonds remaining in the alimentary tract of rats after the ingestion of 2 g of test diet containing 91 micromol plasmalogen. The absorption rate of plasmalogen was nearly 80 mol% after 4 h, comparable to the total phospholipid content in the test diet. In experiment 2, we observed no degradation of the plasmalogen vinyl ether bonds under in vitro conditions simulating those of the stomach and small intestinal lumen. In experiment 3 we confirmed a comparable absorption (36 mol%) by using a closed loop of the upper small intestine in anesthetized rats 90 min after injecting a 10 wt% brain phospholipid emulsion. Feeding a test diet containing 10 wt% brain phospholipids for 7 d increased plasmalogen concentration threefold in blood plasma and by 25% in the liver; however, no increases were seen in blood cells, skeletal muscle, brain, lungs, kidneys, or adipose tissue (experiment 4). We concluded that dietary plasmalogen is absorbed from the intestine and contributes to a large increase in plasmalogen levels in blood plasma.

Animals↗

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↗