Biomedical subjects

F Hirayama

Publications and source records attributed to F Hirayama.

At least 91 records · Page 5Linked to original sources

PubMed1996

Interleukin-4 (IL-4) in combination with IL-11 or IL-6 reverses the inhibitory effect of IL-3 on early B lymphocyte development.

We have previously described a two-step methylcellulose culture system in which individual primitive progenitors from 5-fluorouracil (5-FU)-treated mice were shown to have both myeloid and B lymphoid differentiation capacity. Highly enriched Lin-Sca+FU2d BM cells were cultured in methylcellulose in the presence of Steel factor (SF), interleukin-7 (IL-7), and pokeweed mitogen stimulated spleen cell conditioned medium (PWM-SCM). Primary mixed myeloid colonies were replated after 8-11 days into secondary cultures containing SF and IL-7, which supported the generation of B220+sIgM- pre-B cell colonies. A number of growth factors, including IL-6, IL-11, granulocyte colony-stimulating factor (G-CSF), and IL-12 were shown to be capable of substituting for PWM-SCM to support the B lymphoid potential of primary colonies. B lymphoid potential was not supported, however, in SF + IL-3 or in SF + IL-3 plus any single growth factor (IL-1 to -12, granulocyte-macrophage colony-stimulating factor [GM-CSF], G-CSF, erythropoietin [Epo], leukemia inhibitory factor [LIF], tumor necrosis factor-alpha [TNF-alpha], transforming growth factor-beta [TGF-beta], gamma interferon [IFN-gamma], or insulin-like growth factor-1 [IGF-1]), but was supported in SF + IL-3 + 5% PWM-SCM. Experiments were designed to identify the factor or factors in PWM-SCM that reverse the inhibitory effects of IL-3 on B lymphoid potential. By substituting various cytokine combinations for PWM-SCM, we determined that combinations of IL-4 + IL-6 or IL-4 + IL-11, but not IL-4 alone, can substitute for PWM-SCM to reverse the inhibitory effect of IL-3 on B lymphoid potential. Neutralizing antibodies to IL-4 completely eliminated the activity in PWM-SCM, but antibodies to IL-6 only partially inhibited the activity. IL-11 was not detected in PWM-SCM, and the activity co-purified with IL-4, but not with IL-6. Thus, IL-4 plus IL-6, IL-11, or one or more unidentified growth factors in PWM-SCM can reverse the inhibitory effects of IL-3 on early B lymphocyte development in culture.

Animals↗

PubMed1996

Helicobacter pylori in Japan.

Recent international consensus statements have concluded that Helicobacter pylori is a causal factor in peptic ulcer disease and a Group 1 carcinogen in humans, and that all patients with peptic ulcer associated with H. pylori infection should receive eradication therapy. There are marked differences in the presentation of peptic ulcer disease between Japanese patients and those from other countries, however, and thus a committee of the Japanese Society of Gastroenterology has been set up to develop guidelines for clinical trials in patients with gastric or duodenal ulcers associated with H. pylori. According to these guidelines, eradication therapy should normally consist of dual therapy with a proton pump inhibitor, such as omeprazole, and an antibiotic; a nitroimidazole can be added, however, if necessary. The diagnosis of H. pylori should be made on the basis of a positive culture of the organism or histological examination of gastric biopsies, together with a positive urease test or 13C-urea breath test. Eradication should be confirmed by the same means 4-6 weeks after treatment. Other research is investigating the relationship between H. pylori and gastric cancer, an important issue in view of the high incidence of this condition in Japan. There is evidence that the Mongolian gerbil may be a useful animal model to investigate this question.

Helicobacter Infections↗

PubMed1996

Modulation of early B lymphopoiesis by interleukin-3.

We recently reported that interleukin-3 (IL-3) inhibits B lymphoid lineage expression in methylcellulose culture in a dose-dependent manner. We subsequently used flow cytometric analysis of individual colonies in timed exposure to IL-3 to define more precisely the negative regulatory role of IL-3 in early B lymphopoiesis. When lymphohematopoietic progenitors isolated from 5-fluorouracil (5-FU)-treated mice were cultured in the presence of Steel factor (SF), IL-11, IL-7, and erythropoietin (Epo), B lymphopoiesis appeared to proceed through three stages: lymphohematopoietic proliferation, commitment, and early B lymphoid proliferation. When IL-3 was added to the culture for a 48-hour interval from days 4 to 6 of culture, IL-3 slightly enhanced the formation of pre-B cell colonies. These data appeared to contradict our previous observations that continued exposure to IL-3 from days 0 to 4 or longer severely inhibits B lymphoid potential of the cultured cells. A more frequently timed kinetic observation revealed that in the presence of IL-3 the peak of lymphohematopoietic progenitors was 48 hours earlier but less than one-tenth the number of lymphohematopoietic progenitors in cultures without IL-3. When added to cultures for 48 hours beyond day 6 of culture, IL-3 abrogated the B cell potential of the cultured cells. However, IL-3 failed to negatively modulate B lymphoid progenitors when added on day 14 of culture or later. These observations indicate that IL-3 is a potent negative modulator of the early B lymphopoiesis. IL-3 appears to hasten but suppress the proliferation and commitment of lymphohematopoietic progenitors to B cell lineage. It may also inhibit the proliferation of the progenitors immediately after commitment to B cell lineage.

Animals↗

PubMed1996

Establishment of gastric Helicobacter pylori infection in Mongolian gerbils.

An animal model of Helicobacter pylori infection was obtained with Mongolian gerbils. Culture broth of H. pylori ATCC 43504 was orally administered to the gerbils. Animals were killed 1, 7, 14, 21, and 42 days after the oral inoculation and the stomachs were excised. Colonization of H. pylori was maintained in the stomachs of all animals throughout the study period of up to 42 days. On microscopic examination after immunological and hematoxylin and eosin staining, the organisms were detected in the mucus layer of the gastric epithelium. All gerbils exhibited a slowly progressive but typical gastritis, showing superficial erosion with increasing numbers of infiltrating neutrophils and mononuclear cells. Forty-two days after the inoculation, lymph follicles were detected in the gastric submucosa. These features are similar to the manifestations of H. pylori infection in humans and, accordingly, this model could be of value for studying H. pylori pathogenicity and for research into agents for the treatment of H. pylori infection in humans.

Animals↗

PubMed1995

Negative regulation of early T lymphopoiesis by interleukin-3 and interleukin-1 alpha.

We recently developed a two-step clonal cell culture system for murine lymphohematopoietic progenitors that are capable of producing myeloid and B-lymphoid progenies and characterized their cytokine requirements. We subsequently observed that addition of interleukin-3 (IL-3) or IL-1 alpha to permissive cytokine combinations in primary culture abrogates the B-lymphoid potential but not the myeloid potential of the lymphohematopoietic progenitors. We now describe a similar negative regulation of the T-cell potential of the lymphohematopoietic progenitors. Lin- Ly-6A/E+ marrow cells from 5-fluorouracil-treated mice were plated individually by micromanipulation in methylcellulose culture with steel factor (SF) and IL-11 for 8 days. The resulting colonies were tested for myeloid potential by reculturing part of each colony in secondary myeloid suspension culture. Remainders of individual primary colonies were injected intravenously into scid mice for determination of T- and B-lymphoid potentials. Approximately 10% of the progenitors that differentiated along myeloid lineages in culture reconstituted T- and B-cell compartments in scid mice. However, when scid mice were injected with colonies pooled from cultures containing steel factor, IL-11, and either IL-3 or IL-1 alpha, there was no reconstitution of thymocytes or spleen T cells. These results suggest negative regulatory roles for IL-3 and IL-1 alpha in the early stages of T lymphopoiesis.

Animals↗

PubMed1995

Lymphohematopoietic progenitors of normal mice.

We have identified and characterized the lymphohematopoietic progenitors in the bone marrow of normal mice using a single-step methylcellulose culture assay. Lineage-negative Ly-6A/E (Sca-1)+ progenitors isolated from normal mice were plated in methylcellulose culture containing steel factor (SF), interleukin-7 (IL-7), erythropoietin (Ep), and IL-11. After 16 to 17 days of culture, pre-B-cell-containing multilineage myeloid colonies can be microscopically identified; however, flow-cytometric analysis of individual colonies for B220-positive cells proved superior to in situ microscopic identification of lymphomyeloid colonies. Approximately 10% (6/66) of the mixed colonies without a conspicuous B-cell component had B220-positive cells. The single cell origin of the lymphomyeloid colonies was confirmed by micromanipulation. Although the combination of SF, IL-7, and Ep was sufficient to support formation of lymphomyeloid colonies, addition of IL-11, granulocyte colony-stimulating factor or IL-12 to the combination of SF, IL-7, and Ep increased the number of lymphomyeloid colonies. IL-1 alpha and IL-3 independently inhibited the expression of the B-lymphoid lineage when added to the combination of SF, IL-7, Ep, and IL-11. Approximately four times more lymphohematopoietic progenitors are present in normal mice than in mice treated with 5-fluorouracil.

Animals↗

PubMed1995

The flt3 ligand supports proliferation of lymphohematopoietic progenitors and early B-lymphoid progenitors.

We have examined the effects of the murine ligand (FL) for the flt3/flk2 tyrosine kinase receptor on the proliferation of murine lymphohematopoietic progenitors as well as committed myeloid and B-cell progenitors. In the presence of erythropoietin, FL alone supported scant colony formation from enriched marrow cells of normal mice. However, when it was combined with interleukin-3 (IL-3), steel factor (SF), or IL-11, FL significantly enhanced colony formation. When tested on enriched marrow cells from 5-fluorouracil (5-FU)-treated mice, FL neither enhanced IL-3-dependent colony formation nor synergized with SF in support of colony formation. However, FL synergized with IL-6, IL-11, or granulocyte-colony stimulating factor (G-CSF) in support of formation of various types of colonies, including multilineage colonies. Approximately 30% of these colonies yielded pre-B-cell colonies when replated in secondary cultures containing SF and IL-7, indicating that 2-cytokine combinations, including FL and IL-6, IL-11, or G-CSF can support the proliferation of primitive lymphohematopoietic progenitors. FL, by itself and in synergy with IL-7 or SF, supported the proliferation of B-cell progenitors. These results show that FL has a wide range of activities in early hematopoiesis and B lymphopoiesis.

Animals↗

PubMed1995

In-vivo and in-vitro correlation for delayed-release behaviour of a molsidomine/O-carboxymethyl-O-ethyl-beta-cyclodextrin complex in gastric acidity-controlled dogs.

The in-vivo absorption behaviour of molsidomine from the delayed-release tablets of an O-carboxymethyl-O-ethyl-beta-cyclodextrin complex was investigated using gastric acidity-controlled dogs under fasted and non-fasted conditions. The in-vitro release profiles were generated by changing the pH of the dissolution medium at different rotation paddle speeds. The absorptivity of molsidomine in the high acidity dog was correlated with the pH-changed release profile (pH 1.2 to 7.0 after 2 h), whereas that in the low acidity dog was correlated with the release profile at a constant pH of 7.0. The absorption in fasted dogs was well correlated with the in-vitro release at the low-rotation paddle speed (< 5 rev min-1), whereas that in the non-fasted dogs was correlated with that of high rotation (100 rev min-1). The present results suggested that the in-vivo delayed-release behaviour of the complex is predictable from the in-vitro release profiles generated using pH-variable dissolution testing apparatus at different rotation speeds of the paddle.

Animals↗

PubMed1995

Modulation of B-cell abnormalities in lupus-prone (NZB x NZW)F1 mice by normal bone marrow-derived B-lineage cells.

(NZB x NZW)F1(NZB/WF1) mice spontaneously develop an autoimmune disease characterized by abnormality of haemopoietic stem cells. The present study examined a possible regulatory cell interaction between NZB/WF1 and normal bone marrow cells using radiation-induced chimeras. We demonstrated that the ability of NZB/WF1 bone marrow cells to transfer the typical disease with hypergammaglobulinemia including autoantibodies into lethally irradiated normal recipients was prevented by cotransfer of bone marrow from normal CBA/J mice but not from xid CBA/N mice carrying a selective defect in B-cell function. Flow cytometric analysis revealed that the generation of NZB/WF1 cells was reduced in the mixed chimeras given CBA/J but not CBA/N bone marrow cells. Interestingly, radiation chimeras reconstituted with a mixture of NZB/WF1 bone marrow and CBA/J splenic B cells did not show elevation of serum immunoglobulin levels, although most of the spleen cells were dominated by NZB/WF1 cells. On the other hand, NZB/WF1 B cells maturated in vivo in the presence of CBA/J bone marrow or splenic B cells lost the hyper-responsiveness to lipopolysaccharide (LPS) in the autoantibody production in vitro. These results suggest that radiosensitive normal B-lineage cells have the regulatory activity to ameliorate the hypergammaglobulinemia of NZB/WF1 mice by reducing the generation of NZB/WF1 B cells and/or by correcting their hyper-responsiveness, and that NZB/WF1 mice may have a defect(s) in the regulatory cell function. In addition, CBA/J splenic B cells were shown to modulate the B-cell abnormality even when injected into non-irradiated NZB/WF1 mice manifesting autoimmunity.

Animals↗

PubMed1994

Negative regulation of early B lymphopoiesis by interleukin 3 and interleukin 1 alpha.

We recently developed a two-step methyl cellulose culture system for murine lymphohemopoietic progenitors that are capable of differentiation along the myeloid and B-lymphoid lineages. In this system, two-factor combinations, which include steel factor plus interleukin (IL) 6, IL-11, or granulocyte colony-stimulating factor effectively supported the lymphomyeloid potential of primary colonies. Interestingly, IL-3 could neither replace nor act synergistically with steel factor in maintaining the B-lymphoid potential of the primary colonies although the frequency of colony formation was the same with IL-3 and steel factor. We now report that addition of IL-3 or IL-1 alpha to a permissive system suppresses the B-lymphoid potential of primitive progenitor cells in primary culture in dose-dependent fashion. In vivo transfer of the primary colonies to scid mice confirmed the suppressive effects of IL-3 and IL-1 alpha. In addition, IL-1 alpha inhibited pre-B-cell colony formation in the secondary culture. Once pre-B-cell colonies had formed in secondary culture, neither factor affected the proliferation of the pre-B cells. These results suggest negative regulatory roles for IL-3 and IL-1 alpha in early stages of B lymphopoiesis.

Animals↗

PubMed1994

Synergistic interaction between interleukin-12 and steel factor in support of proliferation of murine lymphohematopoietic progenitors in culture.

We have investigated the effects of interleukin (IL)-12 (natural killer cell stimulatory factor/cytotoxic lymphocyte maturation factor) on the proliferation of murine myeloid and lymphohematopoietic progenitors in methylcellulose culture. In the presence of erythropoietin (Ep), IL-12 alone failed to support colony formation by mononuclear and enriched marrow cells of normal mice. Steel factor (SF) alone supported primarily formation of granulocyte/macrophage (GM) colony formation. However, the combination of the two cytokines yielded a significant number of multilineage colonies. When tested on marrow cells from 5-fluorouracil (5-FU)-treated mice, the combination of IL-12 and SF, but not the single factors, was effective in support of formation of various types of colonies. Approximately 25% of these colonies yielded pre-B-cell colonies when replated in secondary culture containing SF and IL-7, indicating that IL-12 can interact with SF in supporting the development of primitive lymphohematopoietic progenitors. These results demonstrate that IL-12, a cytokine believed to be involved in the development of cell-mediated immune responses, has a wider range of activity, including committed myeloid and multipotent lymphohematopoietic progenitors.

Animals↗

PubMed1994

Effect of 2-hydroxypropyl-beta-cyclodextrin on crystallization and polymorphic transition of nifedipine in solid state.

The glassy state of nifedipine (NP) was prepared in the absence and presence of 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CyD), and its crystallization and polymorphic transition behavior was investigated by differential scanning calorimetry (DSC) and powder X-ray diffractometry. In DSC thermograms, the glassy NP exhibited an endothermic peak at 48 degrees C representing the glass transition of NP, an exothermic peak at 105 degrees C for the crystallization to a metastable form of NP (Form B), an exothermic peak at 125 degrees C for the polymorphic transition of Form B to a stable form of NP (Form A), and an endothermic peak at 171 degrees C for the melting of Form A. The powder X-ray diffractogram of Form B was apparently different from that of Form A. In the presence of HP-beta-CyD, the exothermic peak at 125 degrees C for the Form B to A transition disappeared and a new endothermic peak appeared at 163 degrees C. This new peak was ascribed to the melting of Form B, and the conversion of Form B to Form A was significantly suppressed in HP-beta-CyD matrix. Upon storage at 60 degrees C, the glassy NP was converted to Form A with an activation energy of 18 kcal/mol. The apparent dissolution rate of the NP/HP-beta-CyD (molar ratio 1:1) increased in the order of glassy NP < Form A < Form B, because the glassy NP was readily converted to Form A upon contact with water, resulting in a lower dissolution rate.(ABSTRACT TRUNCATED AT 250 WORDS)

2-Hydroxypropyl-beta-cyclodextrin↗

PubMed1994

In-vivo and in-vitro evaluations of a modified-release oral dosage form of nifedipine by hybridization of hydroxypropyl-beta-cyclodextrin and hydroxypropylcelluloses in dogs.

To maintain a suitable blood level of nifedipine for a long period of time, double-layer tablets consisting of 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CyD) and 3% nonionic surfactant (HCO-60) as a fast-release portion and hydroxypropylcelluloses (HPCs) with different viscosity grades (low, medium and high) as a slow-release portion were prepared, and their in-vitro and in-vivo release behaviours were investigated. Among the seven formulations, the tablet having the mean dissolution time of 0.8-1.3 h gave prolonged plasma nifedipine levels without decrease of AUC after oral administration to dogs. Consequently, the double-layer tablet consisting of HP-beta-CyD with 3% HCO-60/(HPC-low:HPC-medium) in a weight ratio 1/(1.5:1.5) was selected as an appropriate modified-release formulation because it elicited almost comparable retarding effects with superior oral bioavailability compared with those of a commercially available slow-release nifedipine product.

2-Hydroxypropyl-beta-cyclodextrin↗

PubMed1994

Peracylated beta-cyclodextrins as novel sustained-release carriers for a water-soluble drug, molsidomine.

Peracylated beta-cyclodextrins with different alkyl chains (acetyl-octanoyl) were prepared by acylating all hydroxyl groups of beta-cyclodextrin (beta-CyD), and their physical properties were evaluated. These hydrophobic beta-CyDs decreased the release rate of molsidomine, a peripheral vasodilator, in proportion to the lengthening of alkyl chain and suppressed a peak plasma level of molsidomine following oral administration of peracylated beta-CyD complexes to dogs. Among the peracylated beta-CyDs tested, perbutanoyl-beta-CyD maintained sufficient plasma drug levels for a long period of time, while other peracylated beta-CyDs having shorter or longer chains were inappropriate to control the in-vivo release behaviour of molsidomine. The prominent retarding effect of perbutanoyl-beta-CyD was ascribable to the appropriate mucoadhesive property and hydrophobicity, compared with other peracylated beta-CyDs. The present results suggest that perbutanoyl-beta-CyD is particularly useful in modifying the release rate of water-soluble drugs as a novel slow-release carrier.

Acylation↗

PubMed1994

Characterization of the inclusion mode of beta-cyclodextrin sulfate and its effect on the chlorpromazine-induced hemolysis of rabbit erythrocytes.

The inclusion mode of beta-cyclodextrin sulfate (beta-CyD-sul) with a cationic drug, chlorpromazine, was investigated, and the effect of beta-CyD-sul on the hemolytic activity of chlorpromazine was compared with that of parent beta-CyD. The interaction of beta-CyD-sul with chlorpromazine was weaker than that of parent beta-CyD, probably because of the steric or electrostatic repulsion between anionic sulfate groups and hydrophobic phenothiazine moiety. Spectroscopic studies, including pH- and salt-effects, as well as thermodynamic parameters, suggested that both electrostatic and hydrophobic interactions are operative in the inclusion complexation of beta-CyD-sul with chlorpromazine. The inhibiting effect of parent beta-CyD on the chlorpromazine-induced hemolysis of rabbit erythrocytes was accounted for by the decreased fraction of free drug through the complexation. In the case of beta-CyD-sul, the hemolysis and binding of the drug to the erythrocyte membrane was higher than those estimated from the fraction of free drug, probably due to the increased hydrophobicity of the drug through the complexation. However, the chlorpromazine-induced shape change of the erythrocytes was significantly suppressed by beta-CyD-sul, and its inhibiting effect was greater than that of beta-CyD, because of the counterbalance of the opposite effects, i.e., internalization and externalization induced by chlorpromazine and beta-CyD-sul, respectively.

Animals↗

PubMed1994

Cytokine regulation of early B-lymphopoiesis assessed in culture.

Lymphohemopoietic progenitors that are capable of expressing B-cell and myeloid lineages may be cultured from bone marrow cells of adult mice by using a two-step methylcellulose culture system. In this system, the primary colonies expressing myeloid lineages are plated in secondary culture for B-lymphoid colony formation. We have observed that combinations of two factors based on steel factor (SLF), such as SLF plus interleukin (IL)-6, SLF plus granulocyte colony-stimulating factor (G-CSF), and SLF plus IL-11 support the differentiation and proliferation of B-cell progenitors from the lymphohemopoietic progenitors. Surprisingly, IL-3 failed to support B lymphopoiesis either alone or in combination with other factors. In addition, when added to permissive culture conditions, IL-3 and IL-1 independently inhibited the B-cell potential of the primary colonies. The inhibitory effects of IL-3 and IL-1 observed in this in vitro system may be significant in the selection of cytokine combinations for in vitro expansion of hemopoietic stem cells.

Animals↗

PubMed1994

CD43 expression by murine lymphohemopoietic progenitors.

CD43 is expressed by many types of mature blood cells including T-lymphocytes, activated B-lymphocytes, neutrophils, monocytes, and platelets but not non-hemopoietic cells. Defective CD43 is seen in patients with Wiscott-Aldrich syndrome. We have investigated CD43 expression by hemopoietic progenitors of normal and 5-fluorouracil(5-FU)-treated mice. Bone marrow cells were enriched for progenitors by a combination of density centrifugation and negative immunomagnetic selection using lineage-specific monoclonal antibodies. They were then separated based on expression of Ly-6A/E and CD43. Approximately 50% of the Ly-6A/E+ cells of both normal and 5-FU-treated mice were CD43neg-low, while the rest of the cells were CD43bright. The majority of the colony-forming cells including lymphohemopoietic progenitors that gave rise to both myeloid and B-lymphoid lineages were present in the Ly-6A/E+CD43bright cell population. Therefore, Ly-6A/E+CD43bright cells were approximately 2-times enriched for the progenitors relative to Ly-6A/E+ cells. Anti-CD43 antibody is useful in isolation of primitive murine hemopoietic progenitors.

Animals↗

PubMed1993

Quinolone antimicrobial agents substituted with morpholines at the 7-position. Syntheses and structure-activity relationships.

A series of novel 7-substituted 1-cyclopropyl-6,8-difluoro-1, 4-dihydro-4-oxo-3-quinolinecarboxylic acids have been prepared and tested for antibacterial activities and for convulsive activities in combination with nonsteroidal antiinflammatory drug. Structure-activity relationships revealed that 7-(2-(aminomethyl)morpholino) derivative 28 had a better Gram-positive activity than the reference quinolones, such as ciprofloxacin, norfloxacin, and ofloxacin. Its Gram-negative activity was equipotent with those of norfloxacin and ofloxacin but was inferior to that of ciprofloxacin. In mouse systemic infection models, 28 showed an excellent therapeutic efficacy which might result from the potent antibacterial activity and suitable physicochemical properties. Convulsive activities of 7-morpholino derivatives in combination with nonsteroidal antiinflammatory drug fenbufen or its metabolite biphenylacetic acid markedly diminished as compared to those of 7-piperazino derivatives in the electrophysiological, biochemical, and behavioral experiments. These results suggest that 28 (Y-26611) is a novel quinolone with reduced neurotoxic excitatory adverse reaction.

4-Quinolones↗